Chapter 14 Physical Reasoning

Abstract

An intelligent creature or automaton that is set in a complex uncontrolled world will be able to act more effectively and flexibly if it understands the physical laws governing its surroundings and their relation to its own actions and the actions of other agents. This chapter discusses the work of KR researchers that tries to represent commonsense knowledge and carry out commonsense reasoning over some basic physical domains. There is a vast body of computer science and scientific computing that deals in one way or another with physical phenomena; almost all of this lies outside the scope of KR research and, hence, of this chapter. Even within artificial intelligence (AI), there are many types of physical reasoning that are excluded. For instance, the automated visual recognition of a scene is, in a sense, a type of physical reasoning. Image formation is a physical process; the problem in vision is to infer plausible characteristics of a scene given an image of it. This is not considered a problem for KR physical reasoning because the physics involved is too specialized. A single, quite complex, physical process and a single type of inference about the process are at issue; the computational techniques to be applied are highly tuned to that process and inference, and they hardly generalize to any other kind of problem.